Drawing mechanism



Patented May 11, 1926.

UNITED STATES v 1,583,893 PATENT OFFICE...

HEINRICH MEIER, OF UNTERAGERI, SWITZERLAND.

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Applleation med January as, 1920. Serial No. 84,624.

' In order to permit working with considerable draftin s in spinning mills and to save thereby la our, machines, power, space and so on without impairing the quality of the yarn, special drawing mechanisms must be utilized. These drawing mechanisms must be so constructed that the roving in the.- stretching zone is guided and held up to a point that is as close as possible to the pair of drawing rollers. The nearer this guidance is to the pair of drawing rollers the less powerful the clamping of the roving inthe stretching zone must be as otherwise thickened parts in the rovings such as tufts or lumps are formed which are not permissible in the yarn.

Several types of such special drawing mechanisms or frames are on the market which tend to realize the above mentioned effect, for instance by means of pressure roll- I ers made of a light metal, of wood or by pressure rollers having circumferential grooves. The first mentioned pressure rollers h-avin a small weight are prevented from running when fly is deposited thereon; the grooves of the'last mentionedrollers are easily damaged. With other systems which guide the rovings between leather bands up .to thedrawing rollers a perfect clamping action cannot be obtained; further these devices are very complicated, they must be carefull handled and must be attended to by skil ed and reliable attendants.

It is the ob'ect of the present invention to provide a rawing mechanism for spinning machines which is simple, efiicacious and cheap.

A constructional example of the subject matter 'ofthe present invention is illustrated on the accompanying drawings, in

which:

Fig. 1 shows in a side elevation the drawing mechanism and Fig. 2 is a plan view of Fig. 1 on a larger scale, and seen in the directionof the arrow A.

It may be assumed that the constructional example illustrated shows a drawing frame obtained by altering one of the known drawing mechanisms having a pair of feed rollers, a pair of drawing rollers and a pair of intermediate pressure rollers. lower rollers 1., 2 and 3 have not been altered and are mounted in the support consisting of the par-ts 4 and 5 of whlch the latter is adjustable relatively to the former in the The fluted known manner. To the supporting part 5 an upper part 6 is hinged at 7 and in the part 6 the leather covered roller 8 is mounted; the latter and the roller 3 form together the pair of clam ing rollers. The leather covered roller 9 w ich together with the lower roller 1 forms the pair of drawing rollers, is mounted in a bearing piece 10 adjustable along a rod 11 fixed to the part 6. The roller 9 is arrange nearer to the (ill front than in the old drawing mechanism.

The old pressure roller'12 is mounted in the bearing piece 13 having slots 14 in which the pins 15 of the pressure roller 12 are guided.

An intermediate pressure or regulating roller 16 is provided to-cooperate with the lower roller 2, with which also the roller 12 cooperates. The pins 17 of the roller 16 are guided in slots 18 of the bearing part .13.

The portions 19 of the roller 16 which bear on the rovings are reduced indiameter as compared with the remainder of roller 16. This reduction in diameter prevents the formation of tufts and lumps, as only the necessary braking effect is obtained and no' excessiveclamping, the weight of the roller 16 being principally supportedby thelower roller 2. The yarn obtained thereby is very uniform and smooth.

The reduction in diameter of the intermediate pressure roller 16, must be in relation to t e staple to be treated and to the yarn to be spun and the suitable reduction may be obtained in the: following meanner:

Let it be assumed that Louisiana cotton of 28-30 millimetres staple is subjected to a twenty fold drafting for spinning a yarn of No. 30; the roving is then E6 1 .5 In this case the drawing mechanism is so adjusted that the distance from the clampmg point of the rear pressure roller 12 and the middle lower roller 2 to the clamping point the diameter of the roving at the clamping point of the frontpressure roller may be calculated to be millimetres. In order to regulate and uniformly distribute the fibres which are shorter than 30 millimetres the roller 16 must compress the roving so 'far that the diameter of the latter is reduced by one third. That is to say in the above mentioned case the radius of the pressure roller 16 must be reduced by 0.2 millimetres at the places where it cooperates with the rovings as compared with the other parts of the roller.

The regulating roller 16 may be made of a comparatively heavy material so that it does not get blocked by fly adhering to it and in splte ofits heavy weight it does not impa-irthe drafting as the whole weight of the roller does not bear on the rovings and does not cause a clamping of the fibres.

I claim:

1. In a drawing mechanism, in combinamsaeea tion, a pair of feed rollers, a pair of drawin rollers, a pair of intermediate pressure ro lers, and a further intermediate pressure roller cooperating with the lower roller of said pair of intermediate pressure rollers, the portions of said further pressure roller that bear upon the roving having a smaller the portions of said further pressureroller I that bear upon the roving having a radius that is by two thirds of the thickness of the roving at the contacting point between said pressure roller and the cooperating lower roller, smaller than the radius of the other portion of said pressure roller.

In testimony whereof, I have signed my name to this specification.

HEINRICH MEIER. 

